Internal combustion engine



Aug. 30, 1932. J A, BARKEU 1,874,419

INTERNAL-COMBUSTION ENGINE Filed Dec. 29, 1926 3 Sheets-Sheet l 1932- J. A. H. BARKEIJ 1,874,419

INTERNAL COMBUSTION ENGINE Filed Dec. 29, 1926 5 Sheets-Sheet 2 11! 15 526 8 7 7!\ 7 i J 9 9 L In. 556 35,6 N 3 3x 3 30, 193.2. I J BARKEU 1,874,419

INTERNAL: COXBUSTION ENGINE Filed 1926 3 Sheets-Sheet 3 man. FiGB.

S 40 72 0 is a 3 60 s 40 12- Patented Aug. 30, 1932 JEAN A. H. BARK or os ANGELES, CALIFORNIA INTERNAL COMBUSTION ENGINE Application filed December 29,1926. Serial No. 157,845.

My first object is to provide a separate inlet andexhaust around the entire circumference of the cylinder.

My second object is to arrange the ports in athe sleeves and cylinder wall sothat an equal expansion of the cylindrical surfaces is ob.-

tained. V i T Mythird object is to introduce inert gases at the end of the inlet period at the lower end of the cylinder, when the reciprocating piston has reached approximately its bottom positionand'to locate the respective ports in the sleeves sothat theskirt of the piston does not have to be lengthened to cover these ports whenthe pistonis near its top position. It is understood, however, that an additional mixture charge may be equally introduced through these lower inlet ports, if theseports in the sleeves areso arranged, as shown in- Fig. '4, so that the piston chamber hasno connection-with the atmosphere at the end of the exhaust period. Therefore if these ports are connected with the carburetor or another carburetor or fuel mixing means, thesemeans cannot be disturbed by the expansion pressure in they cylinder. In any motor with only inlet portsat the top, it is notpossible to obtain a full charge in the cylinder at high speeds, the.

charge-is thenonly about to 80% of the total displacement of the piston. Therefore the inlet valve closes in such high speed engines very late up to 65, 70 after bottom dead center of the piston. In the present arrangemen't with'two sleeves it is easy to obtain almost full volumes at very high speeds.

Theinlet valve at the top end of cylinder in this case may close about at the timethelower ports-are uncovered by thepiston, it may close much later so that both inlet ports, upper and 40 lower, are open simultaneously. In :multiecylinder engines an eventual backor inertiapressure either way, through the 1 upper or lower ports is quickly absorbed by the other cylinders, if they are all connected with a .45 Single manifold. The'suctionvperiodsfor-the lower ports may be about 121. long, and in a six cylinder these Would already overlap for I the lower ports alone. If these two sets of' inlet ports have not separate carburetors, but a, single one, these suction periods of the upper andlower ports will already overlap with each other ina three or. four cylinder, let alone a six or eight. It is therefore understood also, that ifthe upper inlet and exhaust ports are arranged opposite each other as in standard Knight engines, that these lower inlet ports may becconstructed similarly, as the opening and closing of the inlet and exhaust ports in this latter type is substantially the same, as that shown for the present type.

My fourth object-is to construct both the inlet port for themixture and the inert gas circumferentially to diminish the mixing of these twospecies of gases, during'the latter part ofthe inletperiod, to a minimum.

My fifth object is to move the sleeves during the inletperiod so that the thickness of both sleeves will be available as passage area for the fresh gases from the inlet port in the cyl-' inder situated at the top end thereof.

My sixth object is to introduce a mixture and also inert gas in the cylinder, by preferonce said mixture at the top end of the cylinder, said inert gas, by preference air, at the lower end of the cylinder. V

My seventh object is to introduce at least oneof said gases under the sixth object with a rotative compressor in the cylinder.

My eighth object is to interposeregulating means between said air-compressor and the cylinder to regulate the amount of gas admitted to the cylinder.

My ninth object is to introduce. additional air at the lower end of, the cylinder by means of a compressor, or by means of the atmospheric pressure in the cylinder.

\My tenth object is'to interpose. regulating means between said atmospheric pressure and the cylinderto regulate the amount ofgas admitted to thecylinder. I M y 1 My eleventh object is to interpose third means between the first means to regulate the amount of mixture admitted to the cylinder, and the second means to regulate the amount of air admitted to the cylinder (both of said gases, or only onegas, being admitted under more than atmospheric pressure) so that said first means begin to regulate before said second. means.

hly twelfth object is to combine one or more of said aforesaid objects in a two or fourstroke-cycle engine.

It is my thirteenth object 1st to introduce gas at the top end of the cylinder, and addi= tional gas at'the lower end of the cylinder, or 2nd to introduce gas at the top end of the cylinder and an additional air charge at the lower end of the cylinder, or 3rd to introduce an air charge at the top end of the cylinder, and an additional mixture or air-charge at the lower end of the cylinder. In the original Figure 1 of this application the same three arrangements were proposed for a multicyllnder engine, in which the exhaust at the top w is controlled b a single sleeve and also the inlet at thelower end of the cylinder by said same sleeve, the inlet at the top being regulated by apoppet valve. In the present arrangement all of these portsare controlled by two concentric valves. These additional charges may be introduced by the atmospheric pressure, or by a blower, of the centrifugal or the Roots type under superatmospheric pressure. The advantage of the present system above the standard system, in which the total charge'is introduced by a blower at the top end 01 the cylinder is, that a part of the charge is always introduced by atmospheric pressure and the additional charge by the blower, so that in the present construction the compressor is relieved from apart of the work to introducethe total charge. This amounts to a great deal in multicylinder engine. It is therefore further understood that therefore the present method of charging an internal combustion engine, of the mixture or Diesel type, with a superatmospheric pressure can be efiected equally with a single valve at the top end of the cylinder, further explained in the divisional application No. 447,520, filed April 26, 1930. As a partof the charge can be air, and the additional charge a mixture for the explosive type of engine (an additional air charge for the Diesel type of engine) a single exhaust valve may exhaust the burnt gases and may admit also air via the same valve, whereas in the present construction there is a separate exhaust and inlet port at the top end of the cylinder.

Fig. 1 is a sectional view of the internal combustion engine having two concentric sleeves, each having two diameters over its entire length.

Fig. 2 represents the path of the ports in the two sleeves with respect to the upper and lower ports in the cylinder wall, when the sleeves are moved in such a relative direction, that the upper port in the cylinder wall is the exhaust port and the lower port the inlet port.

Fig. 3 represents the same parts, but the sleeves move in such a direction, that the inlet port in the cylinder is the upper port and the lower port the exhaust port. In F ig.- 1 this movement is represented at the moment of explosion.

Figs. 4:, 8, and 9 represent the inert gas inlet port at the lower ends of the sleeves and cylinder wall and shows the relative position of these ports, when the top edge of the piston reaches its bottom position at the beginning of the exhaust period and the end of the inlet pe riod, and when the lower end of the piston reaches its top position at the end of the exhaust period and theend oi": the compression period. Fig. 10 shows the blower to be used for the scavenging period.

Figs. 5, 6, and 7 show the different sections of the sleeves and cylinder wall.

Fig. 11 is a side view of the tie rod 38.

Fig. 12 is a broken-away portion of Fig. 1 showing a modification in which the outer sleeveis thicker than the inner sleeve.

Fig. 12 shows that the outer sleeve 6 of Fig.

1 can be increased in thickness, greater thanth'at of the inner sleeve, to increase the communication passage between the combustion space 18 and the ports 32 and 33. This difference in thickness can be increased reversely so that the inner sleeve is thicker than the outer sleeve, in which case only the upper port, be it inlet or exhaust, profits by it, having a larger communication passage. In the former case both periods the exhaust and inlet periodbecome greater, in the latter case only the passage for the upper ports, be they exhaust or inlet, increases. Only a part of the sleeve, the upper part may be increased in thickness, to keep the total weight of the sleeve down.

In Fig. 1, 1 is the inner sleeve, 2 the upper edge, 3 the lower edge of the inner sleeve at the top end, 4 the upper edge, 5 the lower edge of a port in said sleeve at the lower end. 6 is the outer sleeve, 7 the upper edge, 8 the lower edge of the upper-end port in said sleeve, 9 the upper edge, 10 the lower edge of the lower top-end port of said sleeve. 11 is the upper edge, 12 the lower edge of the port at the lower end of said sleeve. 13 is thelower edge of the detachable head 17a, 1% is the top edge, 15 is the lower-end edge of the piston 20. 16 is the spark plug, 17 the conical explosion space in the detachable head 17a, 18 the cylindrical explosion space in the inner sleeve between head and piston, 19 the space swept by the piston. 20 is the piston, 21 the wristpin, 22 the connecting rod,

23 the crank pin, 24 the axis of the crankshaft, 25 the chain wheel on said shaft, 26 the chain, 27 the chain wheel on the eccentric shaft, 27a the eccentric shaft, 28 acrank on said shaft connected by rod 28a to wristpin 29 on the inner sleeve 1, 30 a crank on said shaft connected by red 30a to wristpin 31 on the outer sleeve 6. 32 are the. inlet pipes and passages in the cylinder wall, having an upper.

inlet manifold 32, connected withxa crank 40 to a tie rod 38 connected at its. other end with a second crank 41, attached to the throttle 37 in the air-manifold 34, connected to a blower 39. This blower is provided with achainwheel 44, driven by a chain 43, or any other means, from the crankshaft 42.

In Fig. 2 the exhaust port in cylinder and. outer sleeve is shown above the inlet ports therein. Fig. 2 shows the approximate exhaust andinlet areas, if the crank of the. connecting rod of the outer sleeve leads that of the inner sleeve. The same approximate areas. can be obtained if the direction of rota tion of the eccentric shaft is reversed and the crank of the connecting rod of .the outer sleeve is reset approximately 180 in the same direction as the reversal of rotation.

The lower edge 3 of the port in the inner sleeve cooperates with. thelower edge 13 of the reentrant head to open the exhaust and the lower edge 8 of the upper port of the outer sleeve cooperates with the upper edge 2 of the port in the inner sleeve to close said exhaust period. The upper edge 9 of the lower port in the outer sleeve cooperates with the lower edge 3 ofthe port in. the. inner.

sleeve to open and close said inlet period.

In Fig. 3 the inlet port is shown above the exhaust port in the cylinder and outer sleeveLi The exhaust period is initiated by the cooper ation of the lower edge 3 of the port in the inner sleeve with the upper edge 9 of the lowerport in the outer sleeve and closed by the cooperation of the same edges.

The inlet, period is initiatedby the cooperation of the upper edge 2 of the inner sleeve and the lower edge 80f the upper port in the outer sleeve and. is closed by the cooperation of the lower edge 3 of the port in the inner sleeve with the edge 13 ofthe reentrant head. 1 i

If in Fig. 1 the diameter of the piston is 3 inches, its area is 7 .07 inch? The cross-sectional areas of the inner and outer sleeves 7 are respectively 1,23 and 1,33 inch, their thickness being inch. Taking the exhaust and inlet periods at 225. approximately, their areas are greater than those obtainable with the same strokes of said sleeves, if the exhaust and, inlet ports "are placed in the cylinder approximately at same level OPP.

vposite each other as in the standard commercial design.

The arrangement of Fig. 2 has the advantage, that the inner sleeve is less exposed to.

the heat of the, exha st in. the arrange mentof Fig. 3, the inlet capacity however is less than that of the exhaust, and the junk ring 17 b in the head 17a is exposed to the exhaust heat, which diminishes its seal ng q a ities,

The arrangement of Fig. 3 has the disadvantage of greater. heat for the inner sleeve, but the size and height of the exhaust passage is such, that no difficulties with lubrication will result. The outer sleeve is cooled between the ports and is in continuous, contact with the outer surface of the innersleeve. The substantial thickness of the inner sleeve will further prevent local overheating. If the piston were made to cover up this part of a the inner sleeve during the explosion period, this inner sleeve would be further protected against overheating, but this construction is not so advisable in view of the additional inert gas, which can be admitted at the end of the inlet stroke. If the explosion space 17 was entirely located in the head as shown in my previous applications No. 18,456, March 26, 19 25, and No. 129,992, Aug. 18, 1926, the stratified mixture and airrnight intermingle much more during the-latter part of the compression period, and for this reason this construction, which has however great advantages in other respects, is here omitted.

Turning our attention to the, lower part of the cylinder, in connection with Fig. 4, the reader will notice that this latter figure shows the relative positions of the edges 4 and 5 in the inner sleeve and the edges 11 and 12 in the outer sleeve with respect to the upper and lower edges of the additional inlet port 34 and the respective positions of the upper and lower edges 14 and 15 of the piston 20.

At the end of the inlet period the upper edge 14 of the piston clears the inlet port 34 (Fig. 10), and the lower edges 5 and 12 of the inner and outer sleeve respectively, clear this port also. The inlet port for the mixture at the top end is however not yet closed and the inert gases streaming in the space 19 will mix in the lower strata with the incoming mixture.

The location of the ports in the sleeves and cylinder and the position of the respective cranks on the eccentric shaft can however be so adjusted that the inlet closes earlier and before the port 34 is uncovered by the piston, but it is not absolutely necessary to obtain this condition. The greatest thermo-dynamical advantage from a higher average compresion is obtained when the engine is running at about half its maximum speed and force and at that speed the additional air charge does not create enough turbulence to diminish the fuel-air ratio in the upper layers to such an extent that the flame propagation is seriously affected. Only atthelowerspeedranges the simultaneous opening of the two inlet ports will affect theair-i uelratio throughout the gas mass too much. The throttle, however, admitting the additional air charge, can be madeto open when the throttle ofthe mixture is open for about one third. It is of course understood that these two throttles can be operated simultaneously and in any desired relation.

If the port in the outer sleeve is considerably enlarged by bringing the edge 12 so low that continuous overlapping with the cylinder port 34 is obtained, and air charge can also be blown in the cylinder at the end of the exhaust period to scavengethe burnt gases out the exhaust port at the upper end of the cylinder. In that case however the skirt of the piston has to be lengthened'to prevent communicationbetween the blower and the crankcase, if so desired. The space however in the crank case does not change its total. volume during the increment of the pistons and the pressure of the blower would not be interfered with seriously. The lengthening of the skirt causes complication with the connecting rod, though the port 34 could be established partially around the cylinder to allow a recess in said skirt without establishing communication. This arrangement has been fully dealt with in the'copending application No 157,846 of the same date.

Fig. 4: shows further the lower edge 15 of the piston clears the port 34 when the port in the outer sleeve does not communicate with this port. During the beginning of the explosion period both ports in the sleeves areout of re s-"ration with the port during the beginn condition obtains and during the end of the compression period the port in the outer sleeve comes just out of registration with the port 34, when the edge 15 of the piston passes upwardly the inner lower edge 5 oi: the port in the inner'sleeve at the point 0. The skirt of the piston does not have to be lengthened to prevent communication with the crankcase, the quantity of admissible air in the manifold 34 being now controllable simultanoously and correspondingly with the mixture thrott e in the manifold If the manifold 32 does not COZIHHLUllCdtGWllJli all the cylinders the communication between port 34 and crackcase would not interfere with the quantity which can be admitted to the port 34 during the end of the inlet period. It would however entail too much coinplication to operatesimultaneously all the throttles in all the ports 34.- of the. respective cylinders of an engine. For this reason it is preferred to prevent communication and use a single manifoldwith a single throttle, op-

of the inlet period the same erated simultaneously with the mixture throttle.

The Fig. 4 corresponds with the movement of the sleeves shown in Fig. 3 and has to be changed correspondingly for the movement shown in Fig. 2.

Figs. 5, 6, 7 show the cross sections of the ports, sleeves and cylinder walls at different heights and are self explanatory. The number of bridges in the lower ports is increased on account of the passing of the piston rings and on account of the greater forces in longitudinal direction due to the piston pressure during explosion. It is understood that these bridges overlap with each other to increase the valve capacity.

The eccentric shaft is placed on that side of the sleeves where the maximum piston pressure is exerted on the sleeves, bringing thereby the driving point as much below the point of resistance as the unsymmetrical drive of an engine with sleeves allows.

Fig. 8 shows that the edges of the inlet port in the outer sleeve have to be lowered considerably compared with their position in Fig. 4 to establish communication between the blower and cylinder during the end of the exhaust period only, and Fig. 9 shows that the upper edge 11 has to be raised considerably compared with the position shown in Fig. 8, to establish this communication during the end of the inlet and during the exhaust period. In the latter case the port in the outer sleeve is in constant communication with the port 34 in the cylinder and the area for the inlet of air during the exhaust period is shown considerabl greater than that for the inlet of inert gas uring the end of the inlet period. The amount of inert the latter case is considerably less than that necessary for an eiilcient scavenging and cooling during the exhaust periodand should be consequently much smaller in view of the fact, that a blower is necessary if scavenging during the exhaust period is desired.

In Fig. 8 the port in the sleeves, especially that of the inner sleeve can be made so small that no communication between port 34: and crankcase will be established by a piston with a short skirt of which the lower edge 15 will uncover these ports in their upper positions. In Fig. 9 this is impossible and the skirt has to be lengthened or let the blower blow air in the crankcase for cooling purposes.

Fig. 10 shows that the throttle of the two inlet manifolds can be operated simultaneously, it shows the blower and the position of the ports in the sleeve as shown in Fig. 9 during the exhaust period.

The throttle for the additional air inlet can be placed after the blower 39, at 37 connected by rod 38 to mixture throttle, or the throttle can be placed before the inlet of the blower.

blower 3,9 is driven by a chain 43 from the crankshaft 42. The pressure created by this blower (be it a Root-s type or. Rateau type blower) increases with the speed of the engine and the quantity of air that can be introduced in the cylinder can be maintained at any speed and is controllable by the throttle 37. The capacity of .a piston pump diminishes with the speed and would be entirely useless at high speeds and very'short charging and scavenging periods. It is understood, that if the additional air port is only used for the inlet period that the blower is not necessary. If it .is used for both periods, it is understood that'the exhaust at the top end should start very early to prevent damage to the blower.

It is finally understood as shown in Figs. 1 and 4. that the compressor may be entirely omitted, if only a quantity of air is admitted through the lower ports 34 at the approximate end of the inlet period of a four-stroke enginex In that case a certain amount of vacuum may be created by an earlier closing of the "mixtureinlet at' the top end of the cylinder, or by the fact that the atmospheric pressure was not sufficient to fillthe vacuum, created by the piston going downwards, completely. At slowspeeds (idling, or a. little more than idling speeds) no additional air should be admitted, .as this may easily upset the mixture. Therefore the two-throttles of the mixture and the additional ;air should be so regulated that the "additional air 'is only admitted after acertain opening-of the mixture throttle.

It is further understood'that the means to regulate the amount of additional air or the amount of the scavenging charge may consist of other means than "a "throttle "between" said lower ports and a compressor, f. 1. .a blow-off valve to decrease the pressure of said compressor -(see 26 of Fig. 9 of iny Patent 1,722,951) or any other device suitable to regulate accurately thepressure of said compressor at various speeds, and the quantity delivered, dependent or independent of the speed of said compressor. Here again, as in the previous case, the scavenging charge maybecaused to operate after a certain opening of the mixture throttle,:as the scavenging cl". arge leaves a certain amount of airin the cylinder at the end ofthe exhaust stroke, which amount may upset the mixture of the next inlet stroke, as easilyas the amount of additional air.

Again, if both an additionalair'charge and scavengingaircharge is admitted, thethrottle or any other device maybegin to operate after a certain throttle opening, and "said means may be further so regulated that these two quantities areentirely different, as show n by one example in the Figures 4, 8, 9.. In case of, a poppet valve engine, the two amounts may of course be regulated in a similar way by two different lifts of a. poppet valve at the end of the exhaust and inlet period, so that the lift of the last period is smaller than that of the first period (see .Fi g. 9') a .In the last two cases arotative compressor, as shown in Fig. 10, is necessary to inject the scavenging charge through the cylinder as .a sudden expansion of gases in the cylinder may create a small vacuum, but this small vacuum is, as a rule, not always sulficient to admit sufficient air. In the-last case this compressor may be hooked up, of course, withthe same inlet'ports at the lower end of the cylinder, or with different ports, as the vacuum left plus atmospheric pressure at the approximate end of the inlet period may be sufficient to admit an additional air charge. In the first arrangement of these last two constructions there should be some means between the compressor andinlet ports to admit different quantities. after the begin ning of the exhaust and inlet period at the topend of the cylinder, in the second arrange- -ment there should be two different means to regulate these two amounts, and these two means can again be made to cooperate with each other, and with the mixture regulating third means at the top end of the cylinder, as" shown in Fig. 10.1The last two means may again begin to'function after said third means. However, it is possible to start the exhaust period at the top end of the cylinder so early (like in a two stroke engine, :having its exhaust port at the lowerend of the cylinder, approximately at the same level as the inlet port) that the overpressure has disappeared entirely, so that'a compressormay be omitted, and the lower inlet port may be connected with the atmosphere with quantity-regulating means between or' before them. This connection will then only admit additional air after the approximate close of theinlet of mixture at the top end of the cylinder, and no noise will be caused by a partial exhaust through this lower port. In

this arrangement, however, the regulating means should be in operative connection with the mixture throttle as this additional air chargeshould be only admitted after a certain throttle opening. If there are, in the latter case, valvular means between the cylin:

- der and inlet ports inthe cylinder (see Fig.

4), which already obstruct'the escapeof :exhaust gas towards the atmosphere, the exhaust period does not have to start so early.

' Only in case there are no such valvular means .there, as in a cylinder with a single reclprocating piston, of the four strokecycle type with the valves at the explosion end, the exhaustperiod has to start real early before these ports are uncoveredby'the piston.

1.- An internalcombustion engine havinga cylinder, with exhaust and inlet ports above each other, two cylindrical sleeves, each having a single inner and outer diameter over I their entire length, slidable in said cylinder,

' head so thatcommunication between the atmosphere and the combustion space in the inner sleeve is made and cut off during the appropriate phases of the fourstroke cycle and further synchronizing with the position of the piston.

2. An internal combustion engine comprising acylinder, two concentric sleeves in said cylinder, a reentrant head and rec1procating piston in the inner one of said sleeves,

said cylinder and said outer sleeve provided each with two rows of circumferential exhaust and inlet ports, said inner sleeve provided with a single row of circumferential ports, said sleeves reciprocating with a single simple harmonic motion thereby establishing communication between the atmosphere and the space in said inner sleeve during the exhaust and inlet period of a fourstroke cycle 7 and breaking said communication during the compression and explosion phase of said cycle, this sleeve valve engine being characterized by. sleeves having each an inner and outer diameter for each sleeve over 1ts entire surface, the maximum valve capacity of this engine depending upon the cross sectional area of one or both of said sleeves and not depending upon the width of the overlapping of the ports in said sleeves and the width of their registration with the cylinders ports during-the exhaust and inlet period of the Otto cycle.

3. The combination of claim 1 in which said cylinder and said sleeves are provided with air ports at their lower end, said ports in said sleeves and cylinder at least once registering with each other when the upper piston edge approaches itsbottom position during a four stroke cycle, and clears said air ports. a

4. An internal combustion engine, comprising a cylinder, two-concentric cylindrical sleeves, a reentrant head and reciprocating piston in the inner sleeve, said cylinder and said outer sleeve each provided with two 7 rows. of circumferential ports, the inlet ports abovethe exhaust ports in said outer sleeve and'cylinder, said inner sleeve provided with a single row of ports serving as exhaust and inlet ports alternately, said sleeves connected of the ports in the inner sleeve, and cutting of this communication by the cooperation of the same edges of the same ports, the outer sleeve again establishing this communication by the cooperation of the lower edge of the inlet port in the outer sleeve and the upper edge of the ports in the inner sleeve, the inner sleeve breaking again this communication by the cooperation of the lower edge of its port and the lower edge of said reentrant head.

5. A fourstroke-cycle sleeve valve engine with two sleeves, a cylinder provided with two ports, one above the other, ports in said sleeve and cylinder, a reentrant head and reciprocating piston in the inner sleeve, means to move said sleeves with a single harmonic motion, additional ports in said cylinder and sleeves at their lower end, a pressure creating element to blow an additional charge in the combustion space of said engine at least once during the fourstroke-cycle-operation of said engine, and ignition means in the top of said head.

6. A fourstroke-cycle sleeve valve engine with two sleeves, a cylinder, circumferential exhaust and inlet ports in said cylinder and sleeves at their explosion end, additional circumferential scavenging-charging ports at their lower ends near the bottom position of a piston reciprocating in said inner sleeve, a pressure creating element blowing an addition superatmospheric-air-charge through said circumferential scavenging charging ports in said inner sleeve at the end of the inlet period and a scavenging charge after connected to said additional ports in said cylinder to blow an additional superatmospheric-air-charge in said cylinder at the end of the inlet period and a scavenging air charge after the beginning of the exhaust period at the explosion end of said cylinder,*said engine operating on a fourstroke cycle, ignitionmeans in the top of said cylinder. V

8. A fourstroke-cycle internal combustion engine, comprising a cylinder with controlled exhaust and inlet ports at the explosion end thereof, additional circumferential air-inlet ports at the lower end of saidzcylinder un- :covered, at the beginning of the exhaust 7 period and at the end of the inlet period of the fourstroke cycle of said engine, by the piston of said engine reciprocating in said cylinder,-said additional air inlet ports at the lower end of said cylinder connected with a controlled pressure creating element blowing an additional superatmospheric-aircharge in said cylinder attheendiof the inlet period and a scavenging-air-charge in said cylinder after the beginning of the exhaust period at the explosion end of said cylinder, ignition means in the top of said cylinder.

9. A fourstroke-cycle sleeve valve engine, comprising .a cylinder andat least one concentric sleeve valve in said cylinder a piston reciprocating in saidsleeve, a 'reentrant head in said sleeve, circumferential exhaust and inlet ports atfthe 'explosionend of said cyl-' inder and sleeve, circumferential air-scavenging ports at :the lower end ofsaid cylinder and sleeve, saidports in 'saidsleeve uncovering said portsin said cylinder after the beginning of the exhaust period at the explosion end of said sleeve, a throttle regulating the aniountof fuel entering said inlet ports, a pressure creating element regulated bya throttle to blow through saidlower ports a superatmospheric"scavenging charge into said sleeve after the beginning of said exhaust at the upperend of said cylinder, said piston uncovering said portinsaid sleeve-and oylinderonly after the beginning'ofsaid exhaust'period, ignitionmeans in said head.

7 10. A fourstroke internal combustion engine, comprising a cylinder, with controlled exhaust and inlet ports at the explosionend thereof, additional scavenging ports at the lower end of said cylinder, uncovered by the piston and controlled thereby solely, after the beginning of the exhaust period at the upper end .of the cylinder, said additional ports connected with a rotative blower driven by said engine. blowing only ascavenging charge in said cylinder after the beginning of the exhaustat-the explosion end of said cylinder, valvular means between said blower and additional scavenging ports. i

11. A fourstrokejinternal combustion engine, comprising a cylinder with controlled exhaust and inlet ports at the explosion end thereof, additional inlet ports at the lower end of said cylinder, said portsuncovered, at

the approximateend of the inlet period at the top end ofthecylinder, by the piston go- .ing downwardsand closedbythe-same piston going upwards, saidlower ports connected with a pressure creating element, a rotative blower driven by'said engine blowing an additional charge under more than atmospheric pressure in said cylinder and charging said cylinder with a more than atmospheric pressure. a

12. A fourstroke internal combustion-em gine of the explosive type, comprising a cylinder with controlled exhaust and inlet ports at the explosion end thereofladditional charg ing ports'at the lower end thereof, controlled by the upper edge of a piston reciprocating in said cylinder, a controlled pressure creating element connected with said lower ports, valvular means between said element and said additional ports, said element blowing an additional charge in said cylinder after the inlet period is about closed at the top end of said cylinder,*sa'id element being a rotative valvular means between said additional ports and element to control the additional charge blownin said cylinder atthe end of'the inlet period, charging said cylinder with a pressure above one atmosphere.

'14. A fourstroke internal combustion renginefcoinprising a cylinder with controlled exhaust and inlet ports at the explosion end thereof, additional scavenging ports at the lower end of'saidcylinder, covered and uncovered by the piston reciprocating insa'id cylinder, said additional ports connected with a rotat'ive blower driven by said engine, blowing only a scavenging charge in said cylinder after the beginning of: the exhaust at the explosion end of the cylinder, a throttle between said blower and additional scavenging ports. V

15. A fourstroke internal combustion .en gine,,comprising a cylinder with controlled exhaust. andinlet ports at the explosion end thereof, additional inletports at the lower end of said cylinder, said ports covered and uncovered by said piston at the approximate end of the inlet period at the top end of the cylinder, said lower'ports connected with a rotative compressor, a throttle betweensaid compressor and said additional inlet ports, said compressor increasing the charge admit-ted at the .top endof the cylinder to a pressure above atmosphere.

16. A four stroke cycle internal combustion engine, comprising a cylinder with controlled ing scavenging ports at the lower end of said 7 cylinder, said ports connected with a blower, blowing an additional charge in said inlet after the inlet period at the top end of the cylinder is about finished, said blower controlled by a throttle in operative connection with the throttle controlling the inlet at the top end of the cylinder, said first throttle being opened before said second throttle.

17. An internal combustion engine, comprising a cylinder, a piston reciprocating therein, controlled exhaust ports at the top end of said cylinder, additional scavenging ports at the lower end of said cylinder, said ports uncovered and covered by said piston after the exhaust period has started atthe top end of the cylinder, a rotative compressor connected with said scavenging ports, said compressor controlled by a throttle.

18. A four stroke internal combustion engine, comprising a cylinder with a piston reciprocating therein, controlled inlet and exhaust ports at the top end of said cylinder, ad-

ditional scavenging ports at the lower end of said cylinder, connected with a rotative compressor driven by said engine, increasing its pressure with the speed of said engine, said scavenging ports uncovered and covered by said piston after the exhaust period has started at the top end of the cylinder, said rotative compressor controlled by a throttle, said inlet port at the top end of the cylinder vcontrolled by a throttle, said two throttles in operative connection with each other, so that said first throttle is opened after said second throttle for said top inlet for a working charge, ,to prevent dilution of said charge by the residual amount of air from said scavenging charge at low speeds and small inlet charges;

19.. A fourstroke internal combustion engine, comprising, a cylinder, wit-h a piston reciprocating therein, controlled inlet and exhaust ports at the top end thereof, additional scavenging ports at the lower end -of--said cylinders connected with a rotative compressor driven by said engine,

said compressor controlled by' a tl1rottle, said inlet port at the top end of the cylinder controlled by a throttle, said two throttles in operative connection with each other, said blower blowing a scavenging charge in said cylinder after the exhaust period has started at the top end of the cylin- 1 to d 20. A fourstroke cycle internal combustion engine, of the fourstrokecycle of the type with two sleeve valves in a cylinder, a piston reciprocating in the inner one of said sleeves, inlet and exhaust ports in said sleeves and in the inner sleeve during the entire period,

when said piston is near its bottom position, said additional inlet ports in said sleeves and cylinder admitting an additional charge in said cylinder.

21. An internal combustion engine of the ,fourstroke cycle, comprising a cylinder, two

concentric sleeves in said cylinder, a piston reciprocating in the inner one thereof, ex-,

haust and inlet ports at the top end of said sleeves and cylinder, inlet ports at the lower end thereof, said ports so situated that the inlet port in the inner sleeve is moving upwardly over said lower inlet port in said cylinder during the end of the inlet period at the top end of said sleeves and cylinder.

22. The combination of claim 20, in which said lower inlet ports in said inner sleeve are so situated that these ports move upwardly over said lower inlet port in said cylinder during the end of the inlet period at the top end of said sleeves and cylinder. i

23. The combination of claim 20, in which said inner sleeve is moving upwardly during the approximate end of saidinlet period at the top end of the cylinder, said outer sleeve being about in bottom center position during said same period, both of said inlet ports in said sleeves being still in, overlapped relation, when said piston covers up said lower inlet port in said inner sleeve, when moving upwards for compression.

24. An internal combustion engine of the fourstroke cycle, comprising a cylinder, two concentric sleeves in said cylinder, a piston reciprocating in the inner sleeve, exhaust and inlet ports for a charge at the top end of said sleeves and cylinder, additional inlet ports at the lower end of said sleeves and cylinder,"

said latter ports overlapping each other only at the level of said lower inlet ports in said cylinder during the total approximate end of the inlet period, so that said piston going upwards for compression closes said lower inlet period in cooperation with said ports in the inner sleeve, both piston and inner sleeve '0- ing upwards at that time.

25. In a fourstrolze cycle internal combusbeginning of the exhaust period at the topend of the cylinder; v

26. In a fourstroke cycle internal combustion engine, the combination of a cylinder, a piston reciprocating therein, at least one exhaust valve at the top end of the cylinder, at least one inlet valve at the top end of the cylinder to introduce a Working charge under substantially atmospheric pressure, additional inlet ports at the lower end of the cylinder for introducing an additional charge into said cylinder under more than atmospheric pressure during the end of theinlet period, said latter pressure increasing as the speed of the engine increases, means to close said lower ports during the beginnin of the exhaust period at the top end of t e cylinder, when said ports are uncovered by said piston near its bottom position.

JEAN A. H. BARKEIJ. 

